Watch what happens when 49ers defenders take their eyes off of Odell Beckham Jr.

It's common knowledge that the No. 1 rule of defending the Giants is not to let Odell Beckham Jr. get open, guess San Francisco didn't get the memo.

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In the first quarter of Sundays matchup, Niners defenders took their eye off the sophomore receiver for just a second and a second is all it took.

That one second cost San Francisco a most appropriate forty-nine-yards. Looks like this "one year wonder" might be spilling over to the 2015 season.